The current shortage of organs for transplantation mandates that maximum usage be obtained from the scarce resource represented by vital organs. Despite this imperative, many organs that could be transplanted are not transplanted due to limitations on the useful lifetime of organs after they are removed from the body. Thus, there is clearly a need for better preservation solutions for vital organs.
Many preservation solutions have been proposed and patented in the prior art. However, the primary solution used worldwide for most transplantable organs is UW Solution, also known as VIASPAN™, the trade name under which it was initially sold by DuPont Pharmaceuticals. There is no alternative solution that is generally regarded as being superior to UW Solution. Therefore, to be useful, any new organ preservation solutions should be at least competitive with UW Solution.
Despite its widespread use, there is much dissatisfaction with UW Solution as an organ preservation solution. First of all, it requires the addition of expensive additives prior to use, which is inconvenient. Second, UW has to be washed out prior to transplantation of the preserved organ, which is also inconvenient and wastes valuable operating room time. Third, UW solution is viscous and sticky and therefore does a poor job of washing blood out of organs that are flushed with it. To respond to this problem, many centers flush out the blood with a different solution and then flush out this intermediate solution with UW, again wasting time and solution. Alternatively, blood remaining in the organ may account for the failure of a large fraction of transplanted kidneys to function immediately upon transplantation. Fourth, kidneys preserved with UW Solution by simple cold storage for over 24 hours are sufficiently damaged to offset the advantages of organ sharing for improving tissue matching between donor and recipient. Tissue matching is known to have major effects on survival rates five to ten years following transplantation. Therefore, improved preservation after 24 hours of storage could translate into expanded use of well-matched organ transplants and improved long-term survival of organ recipients. This in turn would mean the need for fewer re-transplants after rejection, which would free up the otherwise-needed organs for other recipients.
The limitations and poor efficacy of UW and other organ preservation solutions for preservation for 24 hours and beyond indicate the need for an improved solution.